In MySQL, the ASIN() function returns the arc sine of a number.

You provide the number as an argument when calling the function.

Syntax

The syntax goes like this:

ASIN(X)

Where X is the value for which you’d like the arc sine returned. The argument must be a value in the range -1 to 1. If it’s outside of that range, NULL is returned.

Example 1 – Basic Usage

Here’s a basic example.

SELECT ASIN(0.1);

Result:

+--------------------+
| ASIN(0.1)          |
+--------------------+
| 0.1001674211615598 |
+--------------------+

Here’s what happens when you provide a value of 1.

SELECT ASIN(1);

Result:

+--------------------+
| ASIN(1)            |
+--------------------+
| 1.5707963267948966 |
+--------------------+

And here’s what happens when you provide a value of -1.

SELECT ASIN(-1);

Result:

+---------------------+
| ASIN(-1)            |
+---------------------+
| -1.5707963267948966 |
+---------------------+

Example 2 – Out-Of-Range Values

As mentioned, providing a value outside the range -1 to 1 returns a NULL value.

SELECT ASIN(2);

Result:

+---------+
| ASIN(2) |
+---------+
|    NULL |
+---------+

Example 3 – Expressions

You can also pass in expressions like this:

SELECT ASIN(0.1 + 0.3);

Result:

+---------------------+
| ASIN(0.1 + 0.3)     |
+---------------------+
| 0.41151684606748806 |
+---------------------+

Example 4 – Zero

Zero is within the accepted range.

SELECT ASIN(0);

Result:

+---------+
| ASIN(0) |
+---------+
|       0 |
+---------+

Example 5 – NULL

Passing in NULL returns NULL.

SELECT ASIN(NULL);

Result:

+------------+
| ASIN(NULL) |
+------------+
|       NULL |
+------------+

Return the Arc Cosine

You can also return the arc cosine of a value using the ACOS() function.